Auxiliary structure for preventing deformation and cracking of horizontal suspended surface
By designing the auxiliary structure of polygonal symmetrical units in additive manufacturing, the problem of warping and cracking of horizontal suspended surfaces during printing is solved, and more efficient powder utilization and cost reduction in printing process is achieved.
Patent Information
- Application Number
- CN202420095792.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-16
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2034-01-16
AI Technical Summary
In additive manufacturing technology, horizontal suspended surfaces are prone to warping and arching or cracking during printing due to large temperature gradients. The existing solutions add support structures to control deformation, but it is difficult to control uniform size, which increases material waste and printing costs. .
Design an auxiliary structure composed of polygonal symmetric units, which is set at the bottom of the horizontal suspended surface of the part to be printed, and through rounded corners and uniformly distributed rib structures, the number of support is reduced, the material's tensile stress tolerance is enhanced, and cracking is prevented. and deformation of the arch.
Effectively prevent horizontal suspended surface from deformation and cracking, reduce powder consumption and printing time, reduce printing costs, improve printing efficiency, and simplify post-processing work.
Smart Images
Figure CN222246141U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of additive manufacturing, and in particular relates to an auxiliary structure for preventing a horizontal suspended surface from deforming and cracking. Background Art
[0002] Additive manufacturing technology is an advanced manufacturing technology with distinctive features such as digital manufacturing, high flexibility and adaptability, direct CR1D model drive, fast speed, and rich and diverse material types. Since it is not limited by the complexity of the part shape and does not require any tooling, it has a very wide range of applications. Selective Laser Melting (SLM) is one of the additive manufacturing technologies that has developed rapidly in recent years. It uses powder materials as raw materials and uses lasers to scan the cross-section of three-dimensional entities layer by layer to complete prototype manufacturing. Its basic working process is: the powder feeding device delivers a certain amount of powder to the working platform surface, the powder spreading device spreads a layer of powder material on the bottom plate of the forming cylinder or the upper surface of the formed part, and the laser galvanometer system controls the laser to scan the solid part of the powder layer according to the cross-sectional contour of the layer with an approximately constant spot size and beam energy, so that the powder melts and bonds with the formed part below; when a layer of cross section is sintered, the working platform drops by a layer thickness, and the powder spreading device spreads a layer of uniform and dense powder on it, and scans and sinters a new layer of cross section, and after several layers of scanning and superposition, the entire prototype manufacturing is completed.
[0003] In the above-mentioned additive manufacturing technology, when there is a horizontal suspended surface in the part to be printed, since the melting temperature of the powder is very high and the cooling temperature after molding (i.e., the molding substrate temperature) is low, there is a very large temperature gradient in the process from powder melting to solidification, and the cooling rate reaches 10 4 ℃ / s, the residual stress inside the material is relatively large. In particular, the first few layers of the horizontal suspended surface are very weak, and coupled with the poor thermal conductivity, the subsequent formed entity is prone to warping and even large surface cracking. To address this technical problem, the current solution is to increase the support strength of the suspended surface and tilt printing. The deformation of the tilted printing solution is difficult to control and will cause dimensional differences in the two directions; although normal horizontal printing of the horizontal suspended surface is less difficult to control deformation and has uniform size than tilted printing, it requires a lot of support, which increases the support printing time and makes it more difficult to remove the support. Of course, it also causes material waste and increases printing costs. Utility Model Content
[0004] In order to solve the above-mentioned technical problems existing in the prior art, the utility model provides an auxiliary structure for preventing deformation and cracking of horizontal suspended surfaces. The auxiliary structure for preventing deformation and cracking of horizontal suspended surfaces has a good effect of restraining large surface arching and preventing cracking, and can reduce the number of supports, reduce powder consumption, reduce printing time, and facilitate powder cleaning.
[0005] To achieve the above-mentioned purpose, the utility model provides an auxiliary structure for preventing deformation and cracking of a horizontal suspended surface, the auxiliary structure is arranged at the bottom of the horizontal suspended surface of a workpiece to be printed, and the auxiliary structure is composed of a number of identical symmetrical units spliced in sequence along the horizontal direction, the symmetrical unit is a polygon, and each side of the polygon is composed of a rib, the thickness of all ribs is equal, and the width of all ribs is equal; the width of the rib is 0.5mm-5mm, and the thickness of the rib is 0.5mm-5mm; when there is an angle in the symmetrical unit, at least one angle is rounded, which is recorded as the fillet R1.
[0006] As a further preferred embodiment of the present invention, the polygon is a square, a rectangle, a regular hexagon, a circle or a rhombus.
[0007] As a further preferred embodiment of the present invention, when the polygon is a square, the side length of the regular polygon is 10 mm to 50 mm; when the polygon is a regular hexagon, the radius of the circumscribed circle of the regular hexagon is 10 mm to 50 mm; when the polygon is a circle, the radius of the circle is 5 mm to 25 mm.
[0008] As a further preferred embodiment of the present invention, the thickness of the rib is greater than its width.
[0009] As a further preferred embodiment of the present invention, the rib is a square column, and the right angle where the rib contacts the bottom of the horizontal suspended surface is rounded, which is recorded as the rounded corner R2.
[0010] As a further preferred embodiment of the present invention, the radius of the fillet R1 is 0.2 mm-0.5 mm, and the radius of the fillet R2 is 0.2 mm-0.5 mm.
[0011] As a further preferred embodiment of the present invention, the auxiliary structure is distributed throughout the bottom of the horizontal suspended surface.
[0012] As a further preferred embodiment of the present invention, a support structure is provided below the part to be printed and / or the auxiliary structure, the part to be printed, the support structure and the auxiliary structure are integrally formed by 3D printing, and the auxiliary structure is formed before the part to be printed.
[0013] As a further preferred embodiment of the present invention, the workpiece to be printed, the supporting structure and the auxiliary structure for preventing the horizontal suspended surface from deforming and cracking are made of the same material.
[0014] As a further preferred solution of the utility model, when the workpiece to be printed includes multiple horizontal suspended surfaces, the auxiliary structure is arranged at the bottom of each horizontal suspended surface.
[0015] The auxiliary structure for preventing deformation and cracking of horizontal suspended surfaces of the utility model adopts the above-mentioned technical scheme, so that the auxiliary structure of the present application has the characteristics of dense arrangement, can be evenly distributed below the horizontal suspended surface of the workpiece to be printed, has no weak points, and can better withstand the tensile stress generated by the large horizontal surface with reference to the reinforced concrete structure, and convert the large surface into a relatively small surface, has a strong molding ability, does not increase additional risks, has a certain strength, and can effectively prevent the risks of cracking and arching deformation of the large surface; moreover, the auxiliary structure of the present application not only occupies a small volume, but also reduces the number of supporting structures while ensuring the supporting strength of the horizontal suspended surface of the workpiece to be printed; in addition, the utility model utilizes the support of small units to better complete powder cleaning, thereby reducing powder consumption. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 is a schematic diagram of the original structure of a to-be-printed part with a horizontal suspended surface;
[0017] Figure 2 It is a schematic diagram of the structure of the prior art after the printed part is formed;
[0018] Figure 3 It is a schematic diagram of the structure of the to-be-printed product after it is formed, including the auxiliary structure of the utility model for preventing the horizontal suspended surface from being deformed and cracked;
[0019] Figure 4 for Figure 3 A schematic diagram of the structure without the support structure;
[0020] Figure 5 for Figure 4 sectional diagram of
[0021] Figure 6 for Figure 4 Bottom view of
[0022] Figure 7 for Figure 4 Schematic diagram of the molding process.
[0023] The parts in the figure are marked as follows:
[0024] 1. Base plate, 2. Horizontal suspended surface, 3. Support structure, 4. Ribs, 5. Auxiliary structure for preventing deformation and cracking of the horizontal suspended surface, 6. Parts to be printed. DETAILED DESCRIPTION
[0025] In order to enable those skilled in the art to better understand and implement the technical solution of the utility model, further detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.
[0026] like Figure 3-Figure 6 The auxiliary structure for preventing the horizontal suspended surface from deforming and cracking (hereinafter referred to as the auxiliary structure) is provided at the bottom of the horizontal suspended surface 2 of the workpiece 6 to be printed. The auxiliary structure is composed of a plurality of identical symmetrical units sequentially spliced in the horizontal direction. The symmetrical unit is a polygon, and each side is composed of a rib 4. The thickness of all ribs 4 is equal, and the width of all ribs 4 is equal; the width of the rib 4 is 0.5mm-5mm, and the thickness of the rib 4 is 0.5mm-5mm; when there is an angle in the symmetrical unit, at least one angle is rounded, which is recorded as the fillet R1 (such as Figure 6 Preferably, all the included angles in the symmetrical unit are rounded, and the radius of the rounded corner R1 is 0.2 mm-0.5 mm.
[0027] The width of the rib 4 (see Figure 6 b), the wider the width b, the greater the strength, but its size should not be too large, otherwise the workload of subsequent processing will increase, and the risk of warping and deformation will also increase. The width b of the rib 4 of the present application is preferably 0.5mm-5mm, and the thickness of the rib 4 (see Figure 5 t in the figure), the thickness t can be appropriately increased. The main residual stress of the horizontal suspended surface 2 is tensile stress, and the more obvious is the arching in the stacking direction. The weak points will be torn during the pulling process with the support. Therefore, the thickness t is also preferably 0.5-5mm.
[0028] In a specific implementation, the polygon is a square, a rectangle, a regular hexagon, a circle or a rhombus, etc., and of course it can also be other figures with symmetrical structures. When the polygon is a square, the side length of the regular polygon is 10mm to 50mm; when the polygon is a regular hexagon, the radius of the circumscribed circle of the regular hexagon is 10mm to 50mm (such as Figure 4 When the polygon is a circle, the radius of the circle is 5 mm to 25 mm. The polygon of the present application is preferably a regular hexagon. Several regular hexagons are evenly distributed in an array on a horizontal plane to form a honeycomb structure. The honeycomb structure has strong symmetry, which prevents the problem of weak strength in a certain direction, resulting in serious local cracking and deformation. Moreover, the smaller the size of the regular hexagon, the stronger the rigidity, that is, it has the advantages of both high strength and small volume.
[0029] Preferably, the thickness of the rib 4 is greater than its width, which can ensure structural rigidity and reduce the difficulty of post-processing, while also reducing its own cross-sectional area and reducing its own shrinkage deformation.
[0030] Preferably, the rib 4 is a square cylinder, and the right angle where the rib 4 contacts the bottom of the horizontal suspended surface 2 is rounded, recorded as fillet R2, so as to prevent stress concentration from becoming a large surface weakness. The radius of the fillet R2 is preferably 0.2mm-0.5mm, and of course it can be appropriately increased to increase the structural strength.
[0031] In order to better prevent the horizontal suspended surface 2 from deformation, the auxiliary structure is distributed throughout the bottom of the horizontal suspended surface 2. Of course, in a specific implementation, an auxiliary structure 5 for preventing the horizontal suspended surface from deformation and cracking can also be set at the bottom of the horizontal suspended surface 2 according to design requirements.
[0032] like Figure 3 As shown, a support structure 3 is provided below the workpiece 6 to be printed and / or the auxiliary structure, and the workpiece 6 to be printed, the support structure 3 and the auxiliary structure are integrally formed by 3D printing, and the auxiliary structure is formed before the workpiece 6 to be printed. Figure 7 As shown, the workpiece 6 to be printed, the supporting structure 3 and the auxiliary structure are formed in sequence from bottom to top on the substrate 1.
[0033] Preferably, in order to simplify the printing process, the to-be-printed workpiece 6, the supporting structure 3 and the auxiliary structure 5 for preventing the horizontal suspended surface from deformation and cracking are made of the same material.
[0034] Specifically, when the workpiece 6 to be printed includes a plurality of horizontal suspended surfaces 2 , the above auxiliary structure is disposed at the bottom of each horizontal suspended surface 2 .
[0035] The horizontal suspended surface 2 of the present application refers to the horizontal placement during printing, such as Figure 1 In the prior art, when the flat suspended surface 2 of the workpiece 6 to be printed is large in size, it is necessary to add Figure 2 The strong supporting structure 3 shown here can prevent it from buckling, deformation and cracking. Figure 2 As shown, the support structure 3 included in the workpiece 6 to be printed is complex and dense, which is inconvenient for post-processing after printing, and the printing cost is high and the printing time is long.
[0036] like Figure 3 As shown, by setting the auxiliary structure of the present application under the workpiece 6 to be printed, not only the support strength is guaranteed, but also the support structure 3 of the present application is simple and sparse, which not only facilitates the post-processing work after printing, but also greatly reduces the printing cost and improves the printing efficiency. Figure 3The supporting structure 3 is only arranged below the auxiliary structure, but in a specific implementation, the supporting structure 3 can also be arranged below the workpiece 6 to be printed.
[0037] The above embodiments are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention should belong to the protection scope of the present invention. It should be pointed out that some modifications and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.
Claims
1. An auxiliary structure for preventing deformation and cracking of a horizontal suspended surface, characterized in that: The auxiliary structure is arranged at the bottom of the horizontal suspended surface of the workpiece to be printed. The auxiliary structure is composed of a number of identical symmetrical units spliced in sequence along the horizontal direction. The symmetrical unit is a polygon, and each side of the polygon is composed of a rib. The thickness of all ribs is equal, and the width of all ribs is equal; the width of the rib is 0.5mm-5mm, and the thickness of the rib is 0.5mm-5mm; when there is an angle in the symmetrical unit, at least one angle is rounded, which is recorded as the fillet R1.
2. The auxiliary structure for preventing deformation and cracking of a horizontal suspended surface according to claim 1, characterized in that: The polygon is a square, a rectangle, a regular hexagon, a circle or a rhombus.
3. The auxiliary structure for preventing deformation and cracking of a horizontal suspended surface according to claim 2, characterized in that: When the polygon is a square, the side length of the square is 10 mm to 50 mm; when the polygon is a regular hexagon, the radius of the circumscribed circle of the regular hexagon is 10 mm to 50 mm; when the polygon is a circle, the radius of the circle is 5 mm to 25 mm.
4. The auxiliary structure for preventing deformation and cracking of a horizontal suspended surface according to claim 1, characterized in that: The thickness of the rib is greater than its width.
5. The auxiliary structure for preventing deformation and cracking of a horizontal suspended surface according to claim 1, characterized in that: The rib is a square column, and the right angle where the rib contacts the bottom of the horizontal suspended surface is rounded, which is recorded as the rounded angle R2.
6. The auxiliary structure for preventing deformation and cracking of a horizontal suspended surface according to claim 5, characterized in that: The radius of the fillet R1 is 0.2 mm-0.5 mm, and the radius of the fillet R2 is 0.2 mm-0.5 mm.
7. The auxiliary structure for preventing deformation and cracking of a horizontal suspended surface according to claim 5, characterized in that: The auxiliary structures are distributed all over the bottom of the horizontal suspended surface.
8. The auxiliary structure for preventing deformation and cracking of a horizontal suspended surface according to claim 1, characterized in that: A supporting structure is arranged below the workpiece to be printed and / or the auxiliary structure. The workpiece to be printed, the supporting structure and the auxiliary structure are integrally formed through 3D printing, and the auxiliary structure is formed before the workpiece to be printed.
9. The auxiliary structure for preventing deformation and cracking of a horizontal suspended surface according to claim 8, characterized in that: The workpiece to be printed, the supporting structure and the auxiliary structure for preventing the horizontal suspended surface from deformation and cracking are made of the same material.
10. The auxiliary structure for preventing deformation and cracking of a horizontal suspended surface according to any one of claims 1 to 9, characterized in that: When the workpiece to be printed includes a plurality of horizontal suspended surfaces, the auxiliary structure is arranged at the bottom of each horizontal suspended surface.